Slime control compositions containing phenolic compounds and their use

ABSTRACT

The present invention relates to certain processes and compositions useful for inhibiting and/or controlling the growth of slime in water and, in particular, water employed for industrial purposes. Water employed in the manufacture of pulp paper and water employed in cooling water systems, as well as other industrial waters, provide environments which are conducive to slime formation. The novel compositions of the present invention are mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems. The slime, of course, is objectionable from an operational and/or an aesthetic point of view. Specifically, the invention is directed to and the use of compositions comprising a combination of 5-chloro-4-phenyl-1,2dithiole-3-one and phenolic compounds (or mixtures thereof). The inventive compositions inhibit the growth of slime in water, or more specifically, possess biocidal activity against bacteria, fungi and/or algae. The phenolic compounds contemplated for use in accordance with the present invention are those phenolic compounds which possess the capacity to kill or inhibit the growth of slime-forming microorganisms such as bacteria, fungi and algae. The type phenolic compounds encompassed by the present invention may be exemplified by: phenol, ortho-phenylphenol, 2, 3, 4, 6-tetrachlorophenol, 4-chloro-2-cyclopentylphenol and 2chloro-4-phenylphenol.

United States Patent [1 1 Brink, Jr. et al.

[451 Apr. 8, 1975 1 SLIME CONTROL COMPOSITIONS CONTAINING PIIENOLICCOMPOUNDS AND THEIR USE [75] Inventors: Robert H. Brink, Jr.,Doylestown;

Bernard F. Shema, Glenside; Roger L. Justice, Cornwells Heights; PaulSwered, Philadelphia, all of Pa.

Related U.S. Application Data [62] Division of Ser. No. 160,191, July 6,1971, Pat. No.

[52] U.S. C1. 424/277; 71/67; 162/190; 424/346 [51] Int. Cl A0ln 9/02[58] Field of Search 71/67; 424/277, 346

[56] References Cited UNlTED STATES PATENTS 2,997.380 8/1961 Josephs71/66 3,031,372 4/1962 Brock 424/277 3,824,318 7/1974 Shema et a1. 71/673,829,305 8/1974 Brink, Jr. et a1. 71/67 Primary E.\'aniiner.1ames 0.Thomas, Jr. Attorney, Agent, or FirmAlexander D. Ricci [57] ABSTRACT Thepresent invention relates to certain processes and compositions usefulfor inhibiting and/or controlling the growth of slime in water and, inparticular, water employed for industrial purposes. Water employed inthe manufacture of pulp paper and water employed in cooling watersystems, as well as other industrial waters, provide environments whichare conducive to slime formation. The novel compositions of the presentinvention are mixtures which show unexpected synergistic activityagainst microorganisms, including bacteria, fungi and algae, whichproduce slime in aqueous systems. The slime, of course, is objectionablefrom an operational and/or an aesthetic point of view. Specifically, theinvention is directed to and the use of compositions-comprising acombination of 5- chloro-4-phenyl-1,2-dithiole-3-one and phenoliccompounds (or mixtures thereof). The inventive compositions inhibit thegrowth of slime in water, or more specifically, possess biocidalactivity against bacteria,

fungi and/or algae. The phenolic compounds contem-' plated for use inaccordance with the present invention are those phenolic compounds whichpossess the capacity to kill or inhibit the growth of slime-formingmicroorganisms such as bacteria, fungi and algae. The type phenoliccompounds encompassed by the present invention may be exemplified by:phenol, orthophenylphenol, 2, 3, 4, 6-tetrachlorophenol, 4-ch1oro-2-cyclopentylphenol and 2-chloro-4-phenylphenol.

5 Claims, N0 Drawings SLIME CONTROL COMPOSITIONS CONTAINING PHENOLICCOMPOUNDS AND THEIR USE This is a continuation, division, of applicationSer. No. 160,191, filed July 6, 1971 now U.S. Pat. No. 3,829,305.

BACKGROUND OF THE INVENTION The formationof slime by microorganisms is aproblem which attends many systems. For example, lagoons, lakes, ponds,pools and such systems as cooling water systems and pulp and paper millsystems all possess conditions which are conducive to the growth andreproduction of slime-forming microorganisms. In both once-through andrecirculating cooling systems, for example, which employ largequantities of water as a cooling medium, the formation of slime bymicroorganisms is an extensive and constant problem.

Airborne organisms are readily entrained in the water from coolingtowers and find this warm medium an' ideal environment for growth andmultiplication. Aerobic and heliotropic organisms flourish on the towerproper while other organisms colonize and grow in such areas as thetower sump and the piping and passages of the cooling system. Such slimeserves to deteriorate the tower structure in the case of wooden towers.In addition, the deposition of slime on metal surfaces promotescorrosion. Furthermore, slime carried through the cooling system plugsand fouls lines, valves, strainers, etc. and deposits on heat exchangesurfaces. In the latter case, the impedance of heat transfer can greatlyreduce the efficiency of the cooling system.

In pulp and paper mill systems, slime formed by microorganisms is alsofrequently and, in fact, commonly encountered. Fouling or plugging byslime also occurs in the case of pulp and paper mill systems. Of greatersignificance, the slime becomes entrainedin the paper produced to causebreakouts on the paper machines with consequent work stoppages and theloss of production time or unsightly blemishes in the final product;this, of course, results in rejects and wasted output. The previouslydiscussed problems have resulted in the extensive utilization ofbiocides in cooling water and pulp and paper mill systems. Materialswhich have enjoyed widespread use in such applications include chlorine,organo-mercurials, chlorinated phenols, organobromines, and variousorgano-sulfur compounds. All of these compounds are generally useful forthis purpose but each is attended by a variety of impediments. Forexample, chlorination is limited both by its specific toxicity forslime-forming organisms at economic levels and by the ability ofchlorine to react which results in the expenditure of the chlorinebefore its full biocidal function may be achieved. Other biocides areattended by high costs, odor problems and hazards in respect to storage,use or handling which limit their utility. To date, no one compound ortype of compound has achieved a clearly established predominance inrespect to the applications discussed. Likewise, lagoons, ponds, lakesand even pools, either used for pleasure purposes or used for industrialpurposes for the disposal and storage of industrial wastes become,during the warm weather, besieged by slime due to microoraganism growthand reproduction. In the case of the recreational areas, the problem ofinfection, odor, etc. is obvious. In the case of industrial storage ordisposal of industrial materials, the microorganisms cause additionalproblems which must be eliminated prior to the materials use or thewaste is treated for disposal.

It is the object of the present invention to provide compositions forcontrolling slime-forming microorganisms in aqueous systems, such ascooling water systems and pulp and paper mill systems, and forcontrolling slime formation or microorganism populations in aqueousbodies ingeneral. Moreover, another object of the invention is theprovision of methods for preserving materials and for controllingslime-forming microorganisms in any aqueous system which is conducive tothe growth and reproduction of microorganisms and, in particular,cooling water and paper and pulp mill systems. These methods employ acombination of 5- chloro-4-phenyl-1,2-dithiole-3-one and a phenoliccompound (or mixtures thereof). The phenolic compound must possess theproperty of being biocidally active against bacteria, fungi and/oralgae, i.e., either kill or inhibit the growth of these microorganisms.

In the practice of the invention, the combination is added to theparticular material to be preserved or to the system being treated, forexample cooling water sytems, paper and pulp mill systems, pools, ponds,lagoons, lakes, etc., in a quantity adequate to control theslime-forming microorganisms which are contained by, or which may becomeentrained in, the system which is treated. It has been found that suchcompositions and methods control the growth and occurrence of suchmicroorganisms as may populate these particular systems.

GENERAL DESCRIPTION OF THE INVENTION As earlier stated, the inventivecompositions comprise a combination of 5-chloro-4-phenyl-1,2-dithiole-3-one and a particular phenolic compound (or mixtures thereof) witheither compound being present in such a quantity as to impart asynergistic behavior for the purpose to the composition as a whole.Preferably, the compositions contain a percentage by weight ranging fromabout 5 to about percent of the dithiole- 3-one compound and from about5 to about 95 percent of the phenolic compound. When these twoingredients are mixed either beforehand or by addition to the aqueoussystem individually, the resulting mixtures possess a high degree ofslimicidal activity which could not have been predicted beforehand fromthe known activity of the individual ingredients comprising the mixture.Accordingly, it is therefore possible to produce a more effectiveslime-control agent than has previously been available. Because of theenhanced activity of the mixture, the total quantity of biocide requiredfor an effective treatment may be reduced. In addition, the high degreeof biocidal effectiveness which is provided by each of the ingredientsmay be exploited without use of the higher concentrations of each. Thisfeature is not only important and advantageous from an economical pointof view, but also most desirable from the pollution or ecologicalstandpoints. In this regard, it might be pointed out that the smallerthe amount of a chemical that is required for effective treatment, thesmaller the problem in treating the wastes from these systems. In bothcooling water systems and in paper and pulp mill systems, certaindischarge of waste water, e.g., blowdown in cooling water systems, is anecessity. However, because of the current concern and legislationregarding the discharge of wastes, the effluent waste water must betreated to reduce and, hopefully, to eliminate any undesirableconstituents. This treatment, of course, is time consuming and costly.Accordingly, a reduction in additive usage will result in acorresponding reduction in costs for the treatment of wastes containingthese additives.

To demonstrate the synergism which is obtainable from the combination ofthe phenolic compounds with the 5-chloro-4-phenyl-l,2-dithiole-3-one(supplied by Hercules Corporation under designation S-l6l2), variousexemplary phenolic compounds were chosen. As earlier indicated,synergistic activity can be obtained by combining the dithiole-3-onecompound with phenolic compounds which exhibit growth inhibitory orbiocidal activity with respect to bacteria, fungi and/or algae. Thephenolic compounds which were chosen as representative are as follows:phenol, orthophenylphenol (Dow Chemical Dowicide I); 2-chloro-4-phenylphenol (Dowicide 4); 2, 3, 4, 6- tetrachlorophenol (Dowicide 6);and 4-chloro-2- cyclopentylphenol.

In order to illustrate the synergistic activity, the efficacy and thecomparative effectiveness ofthe inventive compositions, various testswere utilized and will be described following.

growth was determined by turbidity or clarity respectively in themedium. End points for the various mixtures were then compared with endpoints for the pure active ingredients working alone in concomitantlyprepared culture bottles. Synergism was determined by the methoddescribed by Kull et al., [F. C. Kull, P. C. Eisman, H. D. Sylwestrowiczand R. L. Mayer, Applied Microbiology, 9, 538-41, (1961 )]and therelationships, QA/Qu Q /Q 1 is additivity I is antagonism Where, I ISsynergism TABLE l Weight Ratio Quantities Producing End Points (ppm) Q,Q of A to B Q, Q Mixture Q IQ Qn/QlI Q" Q.

100/0 14 (Q0) 95/5 10.45 0.55 l 1.0 0.747 0.0003 0.75 50/50 10.0 10.020.0 0.714 0.005 0.72 5/95 9.0 171 180 0.643 0.086 0.73 0/ l 00 2000(QSPECIFIC EMBODIMENTS It is evident from the data recorded in Table Ithat EXAMPLE I SYNERGISTIC COMBINATION:

Compound A: 5-chloro-4-phenyl-l,2-dithiole-3-one Compound B: Phenol Thecompositions of this Example contained5-chloro-4-phenyl-l,2dithiole-3-one (referred to as Compound A in theTest Equations and in Tables I through 1C and phenol (referred to asCompound B in this Example and in the Test Equations and in Tables 1through 1C) in the weight ratios expressed in the Tables which follow.The compositions were tested for synergistic activity in accordance withthe method described. The synergism test was utilized to evaluate eachof the combinations of this Example and the following Examples.Synergistic Index Test 7 Synergistic activity was demonstrated by adingCompound A and Compound B in varying ratios and over a range ofconcentrations to liquid nutrient medium which was subsequentlyinoculated with a standard volume of suspension of the bacteriumAerobacter aerogenes. Following 2 days incubation, the lowestconcentration of each ratio which prevented growth of the bacteria wastaken as the end point. Growth or nocompositions of the presentinvention function to control slime growth due to microorganisms notonly at equal portions of the respective ingredients, but also wherejust minor amounts of one or the other are present. This discovery ofsynergism at the lower levels is extremely valuable since it illustratesconclusively that the ingredients are compatible over the widepercentage by weight range.

BACTERICIDAL EFFECTIVENESS The bactericidal effectiveness of the mixtureof Compound A and Compound B of this Example is demonstrated by thefollowing Table in which the inhibiting power of a 50/50 by weightmixture of A and B is shown. Aerobacter aerogenes was employed as thetest organism and a substrate technique was utilized. Specifically, thebiocidal mixture was added in gradually increasing quantities tonutrient agar media which was then inoculated with A. aerogenes. Thepreparation was then incubated for 48 hours. The values set forth in theTable indicate the quantity of biocide required, in parts by weight foreach one million parts by weight of the medium, in order to achievecomplete inhibition of the growth of the test organism.

TABLE IA Biocidal Material Compound A (571 Compound B (S /1). InertFUNGICIDAL EFFECTIVENESS In order to test the effectiveness of theinventive rnixtures in respect to fungi. evaluations were made followingthe procedures described by B. F. Shema and J. H. Conkey [Journal forthe Technical Association of The Pulp and Paper Industry, 36, 20A-30A,(1953)]. The described procedure generally entails incorporating thebiocide under test in a nutrient substrate such as agar, malt, etc. andpouring the resulting medium into a Petri dish and allowing the mediumto solidify. A button of fungus inoculum is placed on the surface of thesolidified medium and the medium is incubated for a period of l4 days.After the period, the diameter of the colony is measured and comparedwith the diameter of the button of inoculum originally placed upon thesurface. If there is no increase in the diameter, the growth of thefungus is'considered to be completely inhibited and the treatment levelwhich accomplished this is considered the inhibitory concentration. Thefungal species utilized as the test microorganism to evaluate theefficacy of the present mixture were Penicillium expansum andAspergillus niger.

TABLE I8 percentage kill (based on the initial control count) may becalculated. In this evaluation the water sample was taken from a watertray of a paper machine located in the northeastern United States.

For the purposes of comparison, the mixture of A and B was evaluatedtogether with two recognized commercial biocides, Pentachlorophenol anda Commercial Product.

A perusal of the recorded percentages clearly establishes that thecomposition of the present invention, although less concentrated withrespect to active ingredients as compared to the two commercialproducts, gave excellent rates of kill even at low treatment levels. Asearlier expressed, excellent performance of a biocidal composition atlow treatment levels not only provides a most desirable cost performanceindex, but also provides most desirable advantages from theaspects ofQuantity (ppm) for inhibition Biocidal Material P. expansmn A. nigerCompound A (5% Compound B (5%), Inert (90%) 100 100 TABLE IC Quantity ofPercent kill Biocidal Material biocide (ppm) after 6 hours Compound A(5%). Compound B (S /1). Inert (90%) 5 77 do. do. do. 10 89 do. do do.25 94 do. do. do. 50 99 do. do. do. 100 100 Pentachlorophenol (10091) 582 do. 10 9] do. 25 100 do. 50 100 do. 100 100 Commercial Productactive: Combination of dithiocarbamates) 5 72 do. do. 10 72 do. do. 2573 do. do. 78 do. do. 100 88 SLIME CONTROL EFFECTIVENESS Theinventivemethods and compositions were also tested with respect totheirperformance in the control of slime formation in industrialsystems. In this test an industrial recirculating water was obtainedfrom a system which was currently experiencing problems in respect tothe formation of slime by microorganisms. Such tests do not demonstratethe efficiency of the biocide employed with respect to specific speciesof microorganisms but instead supply a practical demonstration of theefficacy of the biocide tested in relation to those communities ofmicroorganisms which have evidenced their ability to form slime inactual industrial systems.

In the testing of recirculating water samples, a sub strate evaluationwas employed. ln'such testing identical portions of water samples aretreated with varying pollution abatement, waste treatment costs and thepreservation of the ecological strain.

EXAMPLE 2 For mixtures of Compounds A and B, and for Cornpound A andCompound B acting alone, the following results were observed:

SLIME CONTROL EFFECTIVENESS The test procedure used was that explainedin Example 1. For comparative purposes, two commercial TABLE 2 WeightRatio Quantities Producing End Points (ppm) Q, of A to B Q. Qn MixtureQA/Qu QH/Qh Q" Q1 The above evaluation established that the compositionsin the weight ratios evaluated all exhibited synergistic activity. Asset forth in the explanation of the test earlier in this text, when Q./Q,, +Q is less than i. then the two individual components are acting ina synergistic manner.

BACTERICIDAL EFFECTIVENESS The bactericidal effectiveness of thecombination of this Ex-ample was tested in accordance with the procedureoutlined in Example 1. The values obtained are recorded in Table 2Awhich follows:

25 active in kill percentage.

TABLE 2A Quantity (ppm) required for inhibition Biocidal Material of A.aerogenex Compound A (5%). Compound B (5'71). Inert (90%) 300 TABLE 2CQuantity of Percent kill Biocidal Material biocide (ppm) after 6 hoursCompound A (5%). Compound B (57:). lnert (90%) 5 0 do. do. do. l0 l2 do.do. do. 25 35 do. do. do. 50 95 do. do. do. 100 I00 Pentachlorophenol(100%) 5 4| do. 10 59 do. 87 do. 50 100 do. I00 100 Commercial Productactive See Table IC) 5 0 do. do. 10 0 do. do. 25 0 do. do. 18 do. do.l00 28 50 The above data established that the combination ef- EXAMPLE 3fectively inhibited the growth of the particular bacterial StrainSYNERGISTIC COMBINATION Compound A: 5-chloro-4-phenyl-l,2-dithiole-3-oneCompound B: 2-chloro-4-phenylphenol The combination of this Example5-chloro-4-phenyl-l ,2-dithiole-3-one ferred to as Compound A)FUNGICIDAL EFFECTIVENESS The effectiveness of the composition of Example2 was tested in accordance with the procedures set forth in Example 1.The results were:

contained (hereafter reand 2-chloro-4- Table 2B Quantity (ppm) forinhibition Biocidal Material P. expansum A. niger Compound A (S /r).Compound B (5% Inert (90%) 500 500 The composition was quite effectivein controlling fungus growth when it is considered that it containedonly 10 percent active material.

phenylphenol (referred to in this Example as Compound B). As with theprevious Examples, combinations of these ingredients were tested inaccordance 9 with the various test procedures outlined in Example 1. Aswith the previous Examples, the composition was The data obtained isrecorded in the. follwing Tables compared with commercially availableproducts using 3through 3C. samples of water derived from the sump of anair- Synergistic Index Test 3 washer of an industrial cooling watersystem located in For mixtures of Compounds-A and B, and for Com- 5 thenortheastern United States. pound A and Compound B acting alone, thefollowing Again, the slime control effectiveness of the instant resultswere observed: composition even at only 3 hour contact times was su-TABLE 3 Weight Ratio Quantities Producing End Points (ppm) Q Q Of A [O BQ; I I Q]: Mixture QA/Qu H h Q1: OI:

100/0 16.0 l 95/5 15.2 r 0.8 t 16.0 0.950 0.027 0.98 50/50 7.0 7.0 14.00.438 0.233 0.67 5/95 f 1.0 19.0 20.0 0.063 0.633 0.70

The results obtained for this particular combination perior to thecommercial products at low treatment established unequivocally that thetwo ingredients beranges and was significantly better overall ascompared have synergistically together. to the percent active CommercialProduct.

BACTERICIDAL EFFECTIVENESS EXAMPLE 4 The test procedure as described inExample 1 was SYNERGISTIC COMBINATION utilized. The results establishedthat the composition 2 Compound A: 5-chloro-4-phenyl-l,2-dithiole-3 onewas effective in controlling this strain of bacteria. ompoun BI .6-ttr1Chl0r0phnOl TABLE 3A Quantity (ppm) required for inhibition BiocidalMaterial of A. aarugenes Compound (3%), Compound B (5%). lnert (90%) I300 i FUNGICIDAL EFFECTIVENESS V l Synergistic Index Test Thesynergistic activity of the combinations of 5-chloro-4-phenyl-1,2-dithiole-3-one (referred to as Compound A) and2,3,4,6-tetrachlorophenol (referred to in this Example as Compound B)was evaluated in The fungicidal activity of the composition of thisExample was tested in accordance with the procedure previouslydescribed. The results were:

Compound A (5%), Compound B (5%). Inert (90%) g 500 500 SUME CO OEFFECTIVENESS accordance with the test described. The results were asfollows:

The slime control effectiveness of the present com- For mixtures ofCompounds A and B, and for Composition was evaluated using actual papermill water as pound A and Compound B acting alone, the followingexplained under the procedure outlined in Example 1. results wereobserved:

TABLE 3C Quantity of Percent kill Biocidal Material biocide (ppm) after3 hours Compound A (5%), Compound B (5%), Inert 5 5 do. do. do. 10 63do. do. do. 25 76 do. do. do. 50 do. do. do. 100 100 Pentachlorophenol100%) 5 4 do. 10 24 do. 25 71 do. 50 98 do. f 100 100 Commercial Product(30% active See Table 1C) 5 0 do. do. i 10 0 do. do. 7 25 5 do. do. 5019 do. do. 100 23 TABLE 4 Weight Ratio Quantities Producing End Points(ppm) Q Q of A to B Q; Q Mixture Q /Q Q /Q, 0,,

Trial (1) I00/0 18.0

50/50 14.0 14.0 28.0 0.778 0.047 0.83 5/95 4.0 76.0 80.0 0.222 0.2530.47 0/I00 300 Trial (2) 100/0 5.0

The Combinations exh b te a QA/Q QB/QB of from the airwasher sump of acooling tower located in less than 1 which, of course, established thatthe indithe northeastern United States. vidual ingredients operated inconcert to produce a The composition of this Example, as with theprevisynergistic result. ous Examples, exhibited overall desriable andattractive slime control capacity. Of special interest is theBACTERICIDAL EFFECTIVENESS fact that at low percentage activeconcentrations the The efficacy of the compositions of this Example wascompositions were capable of controlling the slimetested in accordancewith the procedure outlined earforming organisms. lier. The results ofthe test clearly established that the combination of the instantinvention is effective even EXAMPLE 5 at low percentages of activeingredients. SYNERGISTIC COMBINATION TABLE 4A Quantity (ppm) requiredfor inhibition Biocidal Material of A. aerogenes Compound A (57:).Compound B (57:). Inert (90%) 300 FUNGICIDAL EFFECTIVENESS Compound A:5-chloro-4-phenyl-l,2-dithioIe-3-one The fungicidal activity of thecomposition of this Ex- S pq B: 4 Chloro'zcyclopemylphenol ample wastested in accordance with the procedure ilfi w Test. previouslydescribed. The result of this evaluation was e synerglstlc actmty of thecombmauons of as follows: 5-chloro-4-phenyl-l.2-dithiole-3-one (referredto as TABLE 4B Quantity (ppm) for inhibition Biocidal Material P.expansum A. niger Compound A (5%), Compound B (5%), Inert (90%) I00 500SLIME CONTROL EFFECTIVENESS Compound A) and 4-chloro-2-cyclopentylphenol(re- As in the previous Examples and in the manner set ferred to in thisExample as Compound B) was evaluforth in the previous Examples. theslime control effecated in accordance with the test described. Theresults tiveness of the composition of Example was tested. The were asfollows: outcome of this evaluation and the data derived using Formixtures of Compounds A and B, and for Comthe Commercial Products areset forth in the following pound A and Compound B acting alone, thefollowing Table. The water sample used in this test was obtained resultswere observed:

TABLE 4C Quantity of Percent kill Biocidal Material biocide (ppm) after6 hours Compound A (57:), Compound B (571), Inert 5 35 do. do. do. [0 45do. do. do. 25 64 do. do. do. 50 85 do. do. do. I00 I00Pentachlorophenol (I007!) 5 41 do. IO 59 do 25 87 do. 50 do. 100 I00Commercial Product (30% active See Table IC) 5 0 do. do. 10 0 do. do. 250 do. do. 50 18 do. do. I00 28 TABLE 5 Weight Ratio Quantities ProducingEnd Points (ppm) Q -l- 0,, Of A to B Q3 Mixture QJ/Qu Qn/Qli Q" 0!;

All of. the combinations tested exhibited a QA/Qa cial interest is thefact that at low percentage active +QB/Qb of less than I which, ofcourse, established concentrations the compositions were capable ofconthat the individual ingredients operated in concert to trolling theslime-forming organisms.

produce a synergistic esult When the inventive compositions are employedin BACTERICIDAL EFFECTIVENESS IS the treatment of coollng or paper millwater, they are preferably utilized in the form of relatively dilutesolu- The efficacy O he C PO U HS 0f thlS mp Was tions or dispersions.For example. a preferred solution tested in accordance with theprocedure outline earlier. comprises b tw 5 percent to 65 percent byweight The results of the test clearly established that the comf hSynergistic bi i i admixture i h i.

bination of the instant invention is effective even at low Gus l nt dsolubilizing agents. ,An example of Percentages of active ingredientssuch a synergistic biocidal product comprises from TABLE 5A Quantity(ppm) required for inhibition Biocidal Material of A. aerogenes CompoundA (5%), Compound B (5%), lnert (90%) 300 FUNGlClDAL EFFECTIVENESS about5 to percent by weight of the phenol, from about 5 to 10 percent byweight of the 5-chloro-4- The fungicidal activity of the composition ofthis Exphenyl-l,2- i hi0l -3-0n n he remainder compose ample was testedin accordance with the procedure of such materials as surfactants,stabilizers, organic solpreviously described. The result of thisevaluation was vents. su h as al an s. ar mati hyd a ns and/ r asfollows: water.

' TABLE 5B Quantity (ppm) for inhibition Biocidal Material P. expansumA. niger Compound A (57:), Compound B (5%), lnert (907:) 500 500 SLI ECON EFFECTIVENESS surfactants such as the alkylaryl polyether alcohols,As in the previous Examples and in the manner set polyether alcohols,sulfonates and sulfates. and the forth in the previous Examples, theslime control effeclike may be employed to enhance the dlsperslblmy andtiveness of the Composition of the Example was-tested stability of thesedispersions. The foregoing solutions of The outcome of this evaluation hthe data derived the biocidalcompositions are utilized in order toinsure using the commerical products are set forth in the folh fapldurflform dlspefslblhty of the blocldes lowing Table The water sampleused in this test was wtthm the industrial water which 15 treated. Ithas been obtained o the Water tray of a paper machine of a found thateither aqueous or non-aqueous solvents are mill located in thenortheastern United States. generally Sultable the Preparatlon ofcomposltlons of TABLE 5C Quantity of Percent kill Biocidal Materialbiocide (ppm) after 3 hours Compound A (571). Compound B (5% lnert 5 38do. do. do. i0 84 do. do. do. 25 86 do. do. do. 50 92 do. do. do. 100 95Pentachlorophenol 1007:) 5 89 (l0. l() 94 do. 25 do. 50 100 do. I00 100Commercial Product (30% active See Table lC) 5 38 do. do. 10 36 do. do.25 9 do. do. 50 0 do. do. 100 36 The composition of this Exampleexhibited overall the invention, e.g., methyl cellosolve, organicsolvents,

desirable and attractive slime control capacity. Of spesuch as thealiphatic and aromatic hydrocarbons, e.g.,

kerosene. Based upon the synergism study as outlined above, it wasascertained that in the treatment of paper mill and cooling water,effecive biocidal actions is obtained when the concentration ortreatment level of the combination or admixture of biocides is between0.5 parts per million to 1,000 parts per million, and preferably between1 and 100 parts per million, based upon the total content of the aqueoussystem treated, such as the total quantity of cooling water or papermill water.

The compositions may also be utilized for the preservation of slurriesand emulsions containing carbohydrates, proteins, fats, oils, etc.;dosage levels for this purpose range in the vicinity of 0.01 to 5percent. The compositions of the invention which can be prepared bymerely combining the respective ingredients and mixing thoroughly atstandard conditions may be fed continuously 'to the treated system,e.g., by means of a metered pump, or may be fed periodically atpredetermined intervals calculated to control the growth ofslime-forming organisms in the system. Naturally, in the treatment ofcooling water, the feeding of the inventive compositions must bedesigned to compensate for blowdown in those systems which employ thatexpedient.

Although the foregoing has been specifically directed to liquidformulations, the combinations of the invention may, of course, beformulated dry with well-known pelletizing agents, e.g, sodium chloride,talc, aluminate, etc. to produce solid pellets or briquettes which areadded directly to the systems to be treated. The pellets or briquettes,of course, dissolve in accordance with predetermined conditions orrates.

In describing the inventive subject matter, the expression composition"has been utilized. However, it is to be understood that physicalcompositions or combinations are not the sole utility of the invention.If, for example, the separate ingredients of the composition" are addedindependently to a particular system, it is intended that this usage ofthe subject matter is within the scope of the invention and is to beconstrued within the broad interpretation of composition and/orcombination."

As would be expected, the inventive composition may be added to thecooling water or paper and pulp mill systems at any convenient point.Naturally, in once-throughor non-circulating systems, the compositionmust be addedupstream from the point or points at which microorganismcontrol is desired. In circulating systems or pulp and paper systems,the compositions must be added at any point provided that the time lapseand the conditons experienced between point of addition and the point atwhich the effect of the composition is to be experienced are not sodrastic as to result in the neutralization of the effect of thecomposition.

Although the invention has been described specifically as being directedto specific compositions comprising 5-chloro-4-phenyl-1,2-dithiole-3-onein combination with the phenol as described in Example 1, thephenylpheno] of Example 2, the 2-chlorophenylphenol of Example 3, thechloropehnol of Example 4 or the pentylphenol of Example 5, it isobvious that homologues, analogues, etc. of the dithiole-3-one compoundcertainly are operable for the purpose. Likewise, the derivatives of thespecially exemplifed organo-bromine compounds also have utility in thepresent inventive concept. Moreover, as earilier described, mixtures ofthe various organo-bromine compounds would also serve the purpose. theprovision, of course, is that the organo-bromine compound possessesbiocidal or growth inhibitory capacity with respect to bacteria, fungi,and algae.

It should be noted that while the evidence has been derived from thetreatemnt .of samples taken from paper and pulp mill aqueous systems,the compositions and methods of the present invention are broadlyapplicable to the treatemnt of aesthetic waters as well as industrialwaters such as cooling waters which are plagued by deposits formed byslime-forming organisms, or by the very presence such organisms.

Having thus described the invention, what we claim 1. A method forcontrolling the growth of the microorganism Aerobacter Aerogenes in anaqueous system in which said microorganism is found which comprisesadding to said system so as to contact said microorganism an effectiveamount of a combination comprising 5-chloro-4-phenyl-l,2-dithiole-3-oneand phenol, where the weight ratio of the dithiole to the phenol is from5 percent to percent to 95 percent to 5 percent.

2. The method of claim 1 where said weight ratio is 50 percent to 50percent.

3. The method of claim 1 where said combination is added to said systemin an amount of from 0.5 to about 1,000 parts by weight of saidcombination per million parts by weight of said aqueous system.

4. A composition which is effective in controlling the growth of themicroorganism Aerobacter Aerogenes in aqueous microorganism system wheresaid is found which comprises 5 chloro-4phenyl-1,2-dithiole-3one phenol,wherein the weight ratio of the dithiole to the phenol is from about 5percent to 95 percent to 95 percent to 5 percent."

5. The composition of claim 4 wherein said weight ratio is 50 percent to50 percent.

1. A METHOD FOR CONTROLLING THE GROWTH OF THE MICROORGANISM AEROBACTERAEROGENES IN AN AQUEOUS SYSTEM IN WHICH SAID MICROORGANISM IS FOUNDWHICH COMPRISES ADDING TO SAID SYSTEM SO AS TO CONTACT SAIDMICROORGANISM AN EFFECTIVE AMOUNT OF A COMBINATION COMPRISING5-CHLORO-4-PHENYL-1,2-DITHIOLE3-ONE AND PHENOL, WHERE THE WEIGHT RATIOOF THE DITHIOLE TO THE PHENOL IS FROM 5 PERCENT TO 95 PERCENT TO 95PERCENT TO 5 PERCENT.
 2. The method of claim 1 where said weight ratiois 50 percent to 50 percent.
 3. The method of claim 1 where saidcombination is added to said system in an amount of from 0.5 to about1,000 parts by weight of said combination per million parts by weight ofsaid aqueous system.
 4. A composition which is effective in controllingthe growth of the microorganism Aerobacter Aerogenes in aqueousmicroorganism system where said is found which comprises 5chloro-4phenyl-1,2-dithiole-3one phenol, wherein the weight ratio of thedithiole to the phenol is from about 5 percent to 95 percent to 95percent to 5 percent.
 5. The composition of claim 4 wherein said weightratio is 50 percent to 50 percent.